Engineer&#39;s valve for air-brakes.



' PATBNTED MAR. 24, 1998.

W.. M. AUSTIN. ENGINEERS VALVE PUR AIR BRAKES.

s .m t U uml/f y l @M L l. if

PATBNTBD MAR. 24, 1908.

W. M. AUSTIN. BNGINEERS VALVE POR AIR BRAKES.

APPLICATION I'ILED 0GT.29, 1903.

2 SHEETS-SHBBT 2.

. reduction has been made to a ply the brakes,

' by theL engineers va ve, enters the train pipe,

UNTTED sTATEs PATENT oEEroE. 2

WALTER MERVILLE AUSTIN, OF SWISSVALE, PENNSYLVANIA, ASSIGNOR TO THEWESTING- HOUSE AIR BRAKE COMPANY, OF PITTSBURG, PENNSYLVANIA, ACORPORATION OF Specification of Letters Patent.

FOR AIR-BRAKES.

Patented March 24', 1908.

Application led October 29, 1903. Serial No. 179,043;

To all whom it may concern:

Be it known that I, WALTER MERVILLE AUSTIN, a citizen of the UnitedStates, residing at Swissvale, in the county of Allegheny and State ofPennsylvania, have invented certain new and useful Improvements inEngineers Valves for Air-Brakes, of which the following is a full,clear, and exact description.

This invention relates to fluidv pressure train brakes andhas specialreference to the device commonly known as the engineers valve.

The object of'my invention is to provide an engineers valve capable ofautomatically maintaining any pressure in the train ipe system that hasonce been determined y a definite movement of the valve handle. Withsuch an engineers valve, incase leakage occurs from `the train pipeafter a given such leakage will be instant y responded to by theengineer's valve and the train pipe charged from the main reservoir tocompensate for the leakage.. Likewise for any reason a pressure be ondthat predetermined the valve will automatically discharge the excesspressure and prevent 'the tendency of the s stem to release 4the brakes.To`accomp ish these functions, my improved valve isso constructed thatthe pressure in the train pipeis balanced againsta constant pressure orforce, so that when one of the pressures is greaterthan the other, vthepreponderatin ressure determines whether a valve shal e opened to chargethe train pipe, or another shall be opened to exhaust the train pipe. Myvalve also is constructed so that vthe manipulator will know that whenhe moves the handle to a certain notch, a corresponding pressure will beestablished in the train pipe, whether that movement is to increase ordecrease the pressure therein. yThus in the application ofbrakes, theengineer will know that when he vmoves the handle to the first notch, hewill eect a reduction say, two pounds, and that this reduction will bemaintained as long as the valve handle remains in the first notch.-Likewise if he moves the handle to the second notch, the pressu re willbe further reduced by two. pounds stituting the main valve seat. Vboltedtogether and D is connected to C by 'pip'eponnection TP; also a portes'leadingto and so maintained. In like manner each notch indicates atrain pipe pressure and the engineer is not required to exercisejudgment or depend upon his gage in charging or discharging the trainpipe.

The construction of a valve adapted to accomplish this object will nowbe described in detail with reference to the accompanying drawing, inwhich:

Figure l is a section of an enffineers valve, some portions being on asliglitly different lane from others; Fig.`2 is a half section and alfelevation, the view being at right angles to Fi 1; Fig. 3 is a lan`ofthe valve with the hand e partiallybro en away; Fig. 4 is a plan of thevalve with the top removed and showing the valve seat, and Fig. 5 is aplan of the movable portion of the manually operated galve which restsupon the valve Seat,

The valve casing is made up of the parts A, B, C and D. A and B arebolted-together and clamped between them is a, disk E con- B and C arebeing threaded on an internal plug p common to both. The joints betweenthe sections of the casing are carefully packed to avoid leakage. Thepart A is a cap and the 'main valve handle F is pivoted therein, theshaft of the handle projecting through the cap and carryin0r adovetailed lug f which engages with a va ve disk a resting upon thevalve seat E and ada ted to rotate thereon when moved by the andle.Around the outer edge of the cap Ais formed a quadrant plate b havingnotches to be engaged by a spring bolt in the handle to hold the-latterat any desired point. Each notch corres onds to a certain train pipepressure, as wil hereinafter appear. The shoulders at each end of thelate indicate the full release position an the emergency position,respectively.

The va ve disk al is provided on its under side with two large cavitiesa and a2, respectively; also with two concentric grooves 0,3 and c4,respectively. On the face of the@ valve seat E there is acavity e, aport e leading through the casing section B to the main reservoirconnection MR also a porte2 leading through the casing section B to the.train an opening AT to the atmosphere, also in the casing section B.This valve seat also contains in its facetwo concentric grooves e4 ande5, respectively, the former connecting with the port e2, leading to thetrain pipe, and the latter connecting with the ort e3, leading to theatmosphere. This va ve seat also contains a series of vertical passagese and a single vertical passage e7, the 1purpose of which will appearhereinafter. t may be stated here, however, that the seven passages e6correspond respectively with seven of the notches in the quadrant plateb, as will hereinafter appear.

In the casing-section B, there is a transverse valve chamber c closed ateach end by the screw caps g, g, and containing two pistons h and iconnected together by a stem j which carries a D-valve k. This valvefaces a seat in which there is a port j leading to the port e2 and thetrain pipe passage, and another port f2 leading to port e3 connectedwith the atmosphere. The pistons h and i have a free fit in the chamberc so that air can feed around them. They are held ,at a neutral orcentral position by springs Z at each end.

Chamber c communicates through a passage' rm, with the cavity e in thevalve seat E.

In the casing section C I place a series of nine flat rings o, one ontop of another, between which are clamped the edges of a series of eightflexible diaphragms wlnch are numbered from l to 8. The middle portionsof these diaphragms are clamped between a series of nine disks g, whichare placed upon a vertical stem g and clamped together. The disks are ofsuccessively increasing external diameter and the rings are ofsuccessively increasing internal diameter, so that the eX- .posedsurface of each successive diaphragm 1s toa predetermined extent greaterthan that of the diaphragm which immediately .precedes it. The sevenvertical passages e 1n the valve seat E are individually continuedthrough the casing section B, respectively to seven of the rings o, inthe manner shown by the passage marked 0 in Fig. 2. The single verticalpassage c7 in the valve seat, leads to the uppermost ring o. Each assageois continued through the ring to w ich it leads by a radial passage o2leading to the space between the two diaphragms clamped on each side ofthat particular rin The radial passage in the upper ring lea s to thespace above the upper or smallest diaphragm, which space is extended toa chamber 03 above the topmost lso Surrounding the stem g/ is a spiralspring s seated at one end against the plug p and bearing 'at the otherend` against the lowest disk g, thus tending to move the stem upward.l Y

The lowercasing section 'D contains a smallvalve 1 seating upward andcontrolling a passage r leading from the space at the left of piston ito the atmosphere' through the chamber r2 and port 13. The lower end ofstem q projects through plug p in a position to strike and open valve r.

The upper end of stern g occupies a similar position with respect toanother small valve t, opening upwardly. This valve controls a passage tleading from the space at the right hand end of piston h to the chambero3 above the topmost disk g.

The operation is as follows: The parts are shown in full release orrecharging position, it being understood that the position of the valvedisk. a upon the valve seat E is as if Fig. 5 were moved over to aconcentric position on Fig. 4 without rotation. In this position` cavitya/ connects together ports e and e2, thus connecting the main reservoirdirectly to the train pipe to quid-'ly recharge the latter. Cavity e. isalso connected with port e thus admitting main reservoir pressurethrough passage lm into the valve chamber c containing pistons i and h.Groove a3 connects together the vertical passage e7 and groove e4, thusadmitting train pipe pressure to the chamber o3 above the upper or No. ldiaphragm. The other vertical passages e6 are all connected with theport e3 and the atmosphere through the grooves a4 and e5. f

When train pipe pressure has risen to the full running pressure, thebraiehandle should be moved to the iirst notch on plate b, thus closingdirect communication between main reservoir and train pipe. ningposition and in this condition the train pipe pressure in the chamber 03above the topmost disk balances the opposing pressure of spring s andvalve stem g occupies a neutral position with respect to both of thevalves r and t, which are both closed.

` To make a service application of brakes, the engineer will move thehandle F to the next notch, or to any notch whose corresponding trainpipe pressure is what is necessary to mal-fie the service stop. In thusmoving the handle, disk ais rotated until groove a3 uncovers one or moreof the vertical passages e6, depending upon the notch at which thehandle was placed This leaves the main reservoir connected with thedouble pistonl chamber through e and m. Train pipe pressure then owsfrom the port c2 through grooves e4, a3, passage e7, as before, and asmany of the passages e as were uncovered by groove a3, and let it be nowassumed that only one of said passages e was uncovered. From the iirstpassage e6 the tram pipe pressure leads through the radial passage o2 inthe second ring and 'enters theannular space between the diaphragrns 1and 2. The pressure under diaphragm 1 1s balanced by the same pressureacting upon the same area This is the run-` above it, but the pressureabove diaphragm 2, being upon a larger area, adds a predetermined amountto the total downward pressure which overcomes spring s and stem g isforced downward, thus opening valve 1' and permitting the main reservoirpressure to escape from the space at the left of piston fi. Piston .stemy' then moves to the left, compressing spring g and causing the D-valve7c to connect passage j (train pipe) wlth passage j2 (atmosphere). Thereduction which then tales place in the train pipe is feltsimultaneously in the space between diaphragms 1 and 2, and as soon as areduction has been made which compensates for the excess of areaor.diaphragm 2 over diaphragm 1, spring s overcomes the downwardpressure and returns the stem to the neutral position, allowing valve 1'to close. When this talfes place, the pressure in the double pistonchamber ilows around piston 'i'. and equalizes on each side thereofpermittingr spring g to return the pistons to the neutral position andcut off train pipe passage j from the atmospheric passage jg. 1f afurther reduction of train pipe pressure is required, say to the amountcorresponding to the fourth. notch from running position, the handle is'moved to the fourth notch position and this uncovers the first four ofthe passages e and admits train pipe pressure on both sides of thediaphragms 1, 2, 3 and 4, but on the upper side only of 5. Valve stem gwill then again move downward and o pen valve r, which will stay'openuntil train'pipe pressure had been reduced enough to compensate for thetotal increase ofdiaphragm area, whereu on the force acting uponthevalve stem wi l again see: a balance and close valve r and the atmosheric escape from the train pipe. Thus sai( diaphragm exposed to thetrain pipe pressure will permit a corresponding reduction of train pipepressure and thus it is that the engineer lnows that when he moves thehandle to a given notch, agiven reduction will be made in the trainpipe. If now, while the handle is at a given notch, there should occur aleakage from the train pipe system, then the total train pressure actingagainst the spring s will not be so great as at the moment when the stemlast found its balance; hence, the spring will move the stem upward andopen valve t, allowing pressure to escape from the right hand side ofpiston 7L through passage t, chamber o3, passage o2 in the topmost ring,passage e7, groove a3v and e4 to the train pipe. The pistons will moveto the right, causing the D-valve to uncover train pipe passage y" andadmit main reservoir pressure from the piston chamber c into the trainpipe to compensate for the leaage. When this compensation has taenplace, valve stem q will be again balanced and will move downward to itsneutral position allowing valve t to close, whereupon the equalizing ofpressure in the piston Achamber will permit the pistons to be moved bythe spring g' to the central or lap position, closing communicationbetween the main reservoir and train pipe. Hence the lea Aage from thetrain pipe system is automatically compensated for without any action onthe part of the engineer.

f, for any reason, after a given reduction, the train pipe pressureshould be augmented from any soirce, it will be seen that the increasedpressure having access to the diaphragms, will again imbalance stem gand force it downward to open valve r. This will be followed by the sameoperation as before, the train pipe being exhausted by the movement ofthe D-valve until a balance is again effected.

If it is desired to increase the pressure in the train pipe to a pointbelow full running train pipe pressure, the brake handle is moved towardrelease position to the notchcorresponding to the increased pressuredesired.' Let this notch, for example, be 3rd notch from runningposition, then the rst three of passages e6 will be in communicationwith train pipe, as previously explained. The remaining passages will bein communication with the atmosphere. All diaphragms below four are nowconnected with the atmosphere. The area of the diaphragm exposed totrain pipe pressure is now smaller than it was when the balance betweenspring s and pressure on diaphragm was last established. Spring s willovercome the pressure on diaphragm causing stem g to move upwards andunseat valve t; and slide valve k will move to admit pressure from mainreservoir to train pipe, as previously described, when the balancebetween train pipe pressure on diaphragm and spring s was disturbed byleakage from the train pipe. This recharging of train pipe will continueuntil a new balance between pressure on diaphragm and `spring s isestablished, when further flow of pressure into the train pipe will beprevented, as previously described.

ln the release of brakes, the valve handle is turned to the full releaseposition shown in Fig. 3, which rotates the valve disk a to the positionfirst described, and thus connects all of the passages e with theatmosphere through groove a, groove e5, which it just overlaps, and porte3. Passage e7 is connected with the train pipe port e2 through groovesa3 and e4 and the train pipe is connected with the main reservoirthrough port e, cavity a and portl e2, thus restoring pressure to thetrain pipe and also restoring the normal train pipe pressure to thechamber 03 above'the top diaphragm, which retains the valve stem g inits balanced and neutral position.

The engineer should now, as before stated, move the handle to the firstnotch or running position, but if hefails to do so, When full runningpressure has been attained, the increased downward pressure of trainpipe iuid on diaphragm N o. l will overcome spring s allowing valve t toclose and opening valve r. Pressure will Anow HOW through passage r andvalve r and port r3 from cavity back of pistoni to atmosp ere. Mainreser-.. voir pressure, which has now leakd by piston 7L, will movevalve stem j and slide valve lc, and open communication through port j',valve lc, port i2 to port c3, thence to atmosphere, thus preventing thetrain pipe from being overcharged.

When the handle'is in running position, cavity eis still incommunication With port e and we have main reservoir pressure in valvechamber c containing pistons i and h. Any decrease of train pipepressure below full running valve pressure Will be restored in thefollowing manner: The pressure on diaphragm N o. y1 being less than fullrunning train pipe pressure, spring s will preponderate and stem g willmove upward unseating valve t, thus opening chamber back of piston h totrain pipe through passage t', valve t and passage e?, groove a3, groovee4 and port e2. Pistons'hI and i and stem j will move to the right undermain reservoir pressure on piston i, against train pipe pressure onpiston h, causing valve k to uncover port y, admitting pressure frommain reservoir through port e', cavity a', cavity e, Rassage m, port y'and port e2 to train pipe. hen train pipe pressure has increased to fullrunning valve, train pipe pressure on diaphragm No. 1 will overcomespring s, causing stem gf to move downward allowing valve t to seat,thus closing passagel t from chamber behind piston h; main reservoirpressure will now leak by piston h until the pressures on both sides ofpiston h are equalized, when spring l will push stem 7c and valve 7c tocentral position covering port y" and preventing further pressure fromflowing into train pipe.

-In making an emergency reduction, the valve handle is thrown to theeXtreme opposite position to that shown i-n Fig. 8, whereupon train pipeport c2 is directly connected with atmospheric port e3 through thecavity a2 and communication from main reservoir to chamber c containingpistons h and i, is cut off by the movement of the rotary valve to aposition Where a plain portion of the valve surface covers cavity c. Itis now impossible for pressure from main reservoir to get into trainpipe regardless of the position of valve r. The reduction of train pipepressure is therefore made instantly through the atmospheric, passage,to which itis opened by the rotation ofthe disk and serves its purposeof meeting the emergency more perfectly than if the reduction was eectedthrough the D-valve in thesame manner as in service applications.

I Wish it to beunderstood that the spring s merely represents a constantforce opposing train pipe pressure and that as such, any other constantor substantiallv constant force. may be substituted. It is likewiseobvious that an arrangement of sliding pistons can be substituted forthe diaphragms 1 to 8. It is likewise understood that I may vary thesize and number of the annular rings, circular disks and diaphragms tosuit the requirements of any individual case.

The utility of this engineers valve is emphasized when used in a systemcontaining triple valves adapted to fractionally increase or decreasethe pressure in the brake cylinders at the will of the engineer, such atriple valve being described in my companion application Serial No.178,389 filed Oct. 24th 1903. The ability to increase or decrease trainpipe pressure at will during an application of brakes without firstreleasing the brakes, is a very important improvement in air brakeapparatus, which is accomplished in the most perfect manner by acombination of the engineers valve described herein and the triple valvedescribed in the said companion application.

Having described my invention, I claim 1. In a fluid pressure brake, thecombination with a train pipe and an engineersbrake valve having aplurality of positions, of a mechanism for altering the train pipepressure and operated by opposing forces, one of which is derived fromthe train pipe pressure, and means controlled by the movement of theengineers brake valve to its different positions for varying theeffective resultant of the force due to train pipe pressure.

2. In a fluid pressure brake, the combination with a train pipe and anengineers brake valve having a plurality of positions, of a valve devicefor controlling the charging and discharging of the train pipe, andoperated by the train pipe pressure in one direction and an opposingconstant force,.and means controlled by the movement of the engineersbrake valve to its different positions for varying the effectiveresultant of the train pipe pressure acting on said valvedevice.

3. In a fluid pressure brake, the combination with a train pipe, of amechanism for altering the train pipe pressure and normally balanced bythe opposing forces of said train pipe pressure and a constant force,and means whereby such balance is automatically maintained at anypredetermined degree of .train pipe pressure.

4. In a fluid pressure brake, the combination of a spring having aconstant force,y

means for balancing different train pipe pressures against said force,and means whereby sucn'balan'ceis automaticaliymamt'aned at anypredetermined degree.

5. In a fluid pressure brake, the combination with a train pipe and anengineers brake valve having a plurality of positions, of a valvemechanism for altering the train pipe pressure and normally balanced bythe opposing forces of said train pipe pressure and a constant force,land means operated by the movement of the engineers brake valve to agiven. osition for automatically maintaining such alance at acorresponding predetermined degree of train pi e pressure.

6. In a fluid pressure brake, the combination with a train pipe, of anengineers brake valve device com rising a main valve mechanism forcon-tro g the charging and dischargingof the train pipe, and anauxiliary valve means for controlling the action of said main valve.

7. In a fiuid pressure brake, the combination with a train pipe, of anengineers brake i valve ldevice complrismg a main valve mech- 'forlcontro the charging and discharging of the train pipe, and an auxiliaryvalve mechanism controlled by the movement of the brake valve handle forgoverning :said main valve.-

8. In a fluid pressure brake, the combination with a train pipe, ofanengineers brake valve device comprising a main valve mechanism forcharging and discharging .the train pipe, a piston .for actuating saidvalve mechanism, and an auxiliary valve means for controlling the fiuidpressure acting on said piston.

9. Ina fluid pressure brake, the combination with a train pipe, of anengineers brake valve device comprising a main valve mechanismforcharging and dischar ing the train pipe, a piston or actuating saivalve mechanism, a' movable abutment subject to train pipe pressure, andauxiliary valve means o p- -erated .by said abutment. for controllingthe pressure acting on said main piston.

110. In a fluid pressure brake, the combination with a train pipe, of anengineers brake valve device comprising a main valve mechanism forcharging Aand discharging the train pipe, a piston or actuating saidvalve mechanism, a movable abutment subject to the opposing pressure ofthe train pipe and a spring, and auxiliary valve means operated by saidabutment for controlling the action of said main piston.

11. In a fluid pressure brake, the combination with valve mechanism forreducing train ipe pressure, of a movable abutment sublject to trainpipe pressure for governing the action of said valve mechanism, andmeans for varying the effective area of said abutvment exposed to trainpipe pressure.

12. In a fluid pressure brake, the combination -With valve mechanism forreducing-tram pipe pressure, of a movable abutment subject to train pipepressure for governing the action of said valve mechanism, and meansoperated by the movement of the engineers valve for varying theeffective area of said i abutment exposed to train pipe pressure.

13. In a fluid pressure brake, the combination with a valve means forcontrolling the charging and discharging of'the train pipe, of a movableabutment subject to train pipe pressure for governing the action of saidvalve means, and means operated by the movement ofthe engineers valvefor varying the effective area of said abutment exposed to train pipepressure.

14. In a fluid pressure brake, the combination with a valve mechanismfor controlling the discharge from the train pipe, of a movable abutmentfor governing the action of said valve mechanism and subject to theopposing pressures of the train pipe and a constant force, and means forvarying the eifective area of said abutment exposed to train pipepressure.

15. In a fluid pressure brake, the combination with a valve mechanismfor controlling the discharge from the train pipe, of a movable abutmentfor governin the action of said valve mechanism and su ject to theopposing ressures of the train pipe and aconstant orce, and meansoperated by the movement of the engineers valve for varying theeffective area of said abutment exposed to train pipe pressure.

16. In a fiuid, pressure brake, the combination with valve means lorcontrolling the train pipe pressure and an auxiliary valve forcontrolling the action of said main valve, of a movable abutment subjectto train pipe pressure for operating said auxiliary valve, and meansfor.varying the effective area of said abutment exposed to train pipepressure.

1S. In a fiuid pressure brake, the combination with a main valve devicefor varying train pipe pressure and an auxiliary valve for controllingthe action of' said main valve, of a movable abutment subject to trainrpipe pressure'for operating said auxiliary valve, and means operated bythe movement of the engineers valve for vary-ing the effective area ofsaid abutment exposed to train pipe pressure.

tion with a main valve for altering train pipe ressure, and an auxiliaryvalve for controling the action of said main valve, of a movableabutment subject to the opposing pressures of the train pipe and aconstant force for operating said auxiliary valve', and means forvarying the effective area of said abutment exposed to train pipepressure.

20. In a fluid pressure brake, the combination with a main valve foraltering train pipe ressure, and an auxiliary valve tor controling theaction of said main valve, of a movable abutment subject to the opposingpressures of the train pipe and a constant lorce for operating saidauxiliary valve, and means operated by the movement of the engineersvalve for varying the effective area of said abutment exposed to trainpipe pressure.

f 21. An engineerfs valve, comprisingr means for charging anddischarging the train pipe, said means being held in a neutral conditionby a balancing of train pipe pressure against a constant forceindependent of the movement of the engineers valve and being moved toeither charge or discharge the train pipe by a yielding or preponderanceof train pipe pressure with respect to said constant force.

22. An engineers valve, comprisingmeans for charging and discharging thetrain pipe, said means being held in a neutral condition by balancingtrain ipe pressure against an opposing constant 'orce independent of themovement of the engineers valve, and being moved to either charge ordischarge the train pipe by a disturbance of the balance in favor ofsaid opposing constant force or train pipe pressure.

23. An engineers valve, comprising a valve having movements in twodirections, one to charge and the other to discharge the train ipe, incombination with two valves, one adbpted to control pressure to movesaid first mentioned valve in one direction and the other adapted tocontrol pressure to move said valve in its other direction, and amovable element adapted when moved in one direction to open one of saidtwo valves, and

when moved in the other direction vto open the other of said two valves,said movable element being-exposed to a constant force on one side andto train pipe pressure on the other side.

24. Alt engineers valve, comprising a valve having movements in twodirections, one to charge and the other to discharge the train pipe, incombination with two valves, one adapted to control pressure to movesaid first mentioned valve inone direction and the other adapted tocontrol pressure to move said valve in its other direction, and amovable element adapted when moved in one direction to o en one of saidtivo valves, and when move in the other direction to open the other ofsaid two valves, said movable element being exposed to a constant forceon one side and to train pipe pressure on the other side and means forvarying the area of said movable element exposed to said train pipepressure. 4

25. An engineers valve, comprising means for altering train pipepressure, in combination with a movable element controlling theactuating of said means, said movable elef ment being exposed on oneside to a constant force and on the other side to train pipe pressureand means for varying the effective area of said movable element exposedto train pipe pressure.

26. An engineers valve, com rising means for charging and discharging te train pipe, in combination with a movable element adapted to controlsaid charging and discharging means, said movable element consisting ofa stem having attached thereto a series of diaphragms of graduated area,a

constant force acting upon said stein to said diaphragms in oppositionto said constant force.

28. An engineers valve, com rising means for charging and discharging te train pipe, in combination with a movable element adapted to controlsaid char Iig and discharging means, said movable e ement consisting ofa stein having attached thereto a series lof diaphragms of graduatedarea, a constant force acting upon said stem to move it in one directionand manually operated means for directing air pressure -against anydesired number of said diaphragms in' opposition to said constant force.

29. In an engineersvalve, a chamber containing inain reservoir pressureand a valve balanced on opposite sides by said pressure, said valvecontrolling the charging anddischarging of the train pipe, exhaustpassages leading from the opposite sides of said valve, a valve in eachpassage and a movable ele'- iiient controlling both valves in sai\dassages and itself controlled by train pipe p essure.

30. In an engineers valve, a chamber containing,main-reservoir pressureand a valve balanced on opposite sides by said pressure,

springs tending to hold the valve at a neutra] position, said valvecontrollirigthe'charging and discharging of the train pipe, exhaustpassages leading from the opposite sides of said valve, a valve in eachassage and a 5 movable element controlling otli Valves in said passagesand itself controlled by train pipe pressure. i 1

31. In an engineers valve, a movable element controlling the chargingand discharg 10 ing of the train pipe, said element being exposed on oneside over a given area to train pi e pressure and being exposed on theother si e to a constant force, in combination with means for increasingthe area exposed to train pipe pressure, for the urpose set forth. 15

In Witness whereof, I sugscrlbe my signature, in presence of tWoWitnesses.

WALTER MERVILLE AUSTIN.

Witnesses:

GEO. W. FIELDHoUsE, JOHN H. MATHIAs.

